1. Field of the Invention
The present invention relates to a manufacturing method for a thermal head.
2. Description of the Related Art
There has been conventionally known a thermal head which is used in a thermal printer to be installed frequently in a small-sized information equipment terminal typified by a small-sized handy terminal, and which performs printing on a heat-sensitive recording medium by selectively driving some of a plurality of heating resistors based on printing data.
In the thermal head as described above, it is known to adjust resistance values of heating resistors (hereinafter, this adjustment is referred to as “resistance value trimming”) in order to manage amount of heat generated by the heating resistors (for example, see Japanese Patent Application Laid-open No. 2001-63123). In a method for the resistance value trimming, which is described in Japanese Patent Application Laid-open No. 2001-63123, a predetermined voltage is applied to the respective heating resistors to detect heating temperatures thereof, and trimming energies are applied to the respective heating resistors to adjust heating characteristics thereof including resistance values, heat capacities, and the like so that the heating temperatures can be a target heating temperature within a predetermined range, whereby the heating temperatures are made uniform.
However, in the method for the resistance value trimming, which is described in Japanese Patent Application Laid-open No. 2001-63123, in order to set the target heating temperature of the heating resistors, the predetermined voltage must be applied to each of the heating resistors to measure the heating temperatures of all the heating resistors, resulting in a disadvantage in that much expense in time and effort is required. Further, there is a problem in that a large-scale apparatus such as a microscope-type infrared radiation thermometer must be used in order to measure the heating temperatures of the respective heating resistors.